Referee Mike Dean sent off Arsenal defender Laurent Koscielny for wrestling Edin Dzeko to the floor, and although the Bosnian saw his penalty saved, via the post, City - who last won in the league at Arsenal in 1975 - took command with first-half goals from James Milner and then a tap-in for Dzeko.

Arsenal, who lost more ground on the top four, regrouped after the break, but were not able to find a way back into the game, even when City captain Vincent Kompany was sent off with 15 minutes left for a two-footed tackle on Jack Wilshere.

There had been a security alert outside the stadium before kick-off, which saw police cordon off access to the approach roads for the best part of an hour following a suspect package in a car park nearby.

The game burst into life on eight minutes. Koscielny grappled Dzeko to the floor in the six-yard box, leaving the referee little option but to award a penalty and punish the Arsenal defender with a red card.

The home fans, though, will inevitably have felt a sense of injustice, which was appeased somewhat when Wojciech Szczesny pushed Dzeko's spot-kick onto the post with his legs - and gratefully collected the ball as it rolled back along the goalline.

Midfielder Alex Oxlade-Chamberlain was immediately sacrificed as German centre-half Per Mertesacker came into the defence.

After weathering a spell of City pressure, Arsenal finally went on the offensive, with lone striker Theo Walcott, yet to agree a new contract extension, crashing the ball over after it dropped out to the edge of the penalty area following a corner.

City, though, took the lead on 21 minutes.
Dean again infuriated the home supporters by awarding a free-kick for Lukas Podolski's challenge on Javi Garcia. The ball was quickly worked out to Carlos Tevez, and his intelligent pass into the Arsenal area split the defence as Milner ran through to smash the ball high into the top-left corner.

Buoyed by a first Premier League goal at Emirates Stadium since DaMarcus Beasley's effort in 2007, City were now in full flow.
Garcia nodded wide from 10 yards after another good delivery from Gareth Barry.

Just after the half-hour and it was 2-0. Milner turned provider down the right and his low cross through the six-yard box was turned goalwards by Tevez. Szczesny made a fine reaction save at full-stretch, but could do little as the loose ball dropped to Dzeko who rolled it into an empty net, before the Bosnian frontman displayed a T-shirt with a message to friends from his "neighbourhood'' back home.

Arsenal had to respond quickly to force themselves back into the game and keep alive hopes of closing in on fourth spot, as Podolski's snapshot warmed Joe Hart's hands.
It was almost 3-0 and game over just before half-time when Garcia's effort was headed off the line by Wilshere.

City started strongly following the restart, with Dzeko heading Milner's deep cross over at the far post as Arsenal called for offside.
With 33 minutes left, Podolski was replaced by France striker Olivier Giroud.

Midfielder Abou Diaby - who had been out since September with a thigh problem - was then brought off as Wales midfielder Aaron Ramsey came on.
Arsenal were now more menacing going forwards, but still risked being overrun in midfield on the swift counter attack.

Dzeko sent Tevez clear through the middle after breaking down the left, but Szczesny made a brilliant stop as the City striker tried to run around the Arsenal keeper.
Giroud headed over from six yards after Bacary Sagna's free-kick from the right.

The red card was out again on 75 minutes, this time shown to City skipper Kompany when he clattered into Wilshere, when although the defender's sliding challenge won the ball his feet were raised.
Mancini brought on Joleon Lescott for Tevez, while Arsenal threw Mertesacker up front.

Walcott saw his effort hacked off the line by Lescott in stoppage time, but it was too little too late for Arsenal, who must now lift themselves for Wednesday night's crunch FA Cup replay against Swansea.